The Human Body and Its Enemies: A Textbook of Physiology Hygiene and Sanitation by Carl Gottfried Hartman Lewis Bradley Bibb

Author:Carl Gottfried Hartman, Lewis Bradley Bibb
Language: eng
Format: epub
Publisher: World Book Co.
Published: 1913-03-25T05:00:00+00:00

Figure 119.— Burning the oxygen out of a jar (/) of air; Af, match stuck into a piece of potato in a dish (D) of water. i4, level of water after removal of oxygen by burning of match-head.

Figure 120, — Experiment to show that clear lime water made with fresh lime will become milky from carbon dioxid in expired air.

SUMMARY

Respiration is the taking in of oxygen and the giving off of carbon dioxid. The oxygen is taken from the air and is used in the body for oxidation. The oxygen unites with the carbon of our food and tissues, producing carbon dioxid, a waste substance, injurious to the body. Every cell in the body uses oxygen and gives off carbon dioxid. The blood carries the oxygen to the cell and the carbon dioxid away from it. The carbon dioxid leaves the body in the breath, as can easily be seen by experiment.

QUESTIONS

I. Define respiration. 2. How is carbon dioxid formed in the body? 3. In a stove? 4. Why is oxygen needed? 5. Why do we need more oxygen when rumiing than when sitting? 6. What conmion observation seems to prove this? 7. How does each cell secure oxygen and get rid of carbon dioxid (Figs. 113 and 117)? 8. How does the whole body get rid of carbon dioxid and take on oxygen? 9. How can you prove that about one fifth of air is oxygen? 10. How can you show that carbon dioxid is given off in the breath?

CHAPTER XXXn. THE Am PASSAGES

In the last chapter it was shown how the cells of the body take oxygen out of the blood and give off carbon dioxid into it. This is called internal respiration. In the lungs the blood exchanges carbon dioxid for oxygen with the air that is breathed in and out. The breathing of air in and out of the lungs is called external respiration. How external respiration is carried on will be explained in this chapter.

The Breathing Organs. The breathing organs, or the organs of respiration, are the lungs and the air passages carrying the air to and from the lungs. The bones of the chest and the muscles attached to them cause the air to enter the lung through the air passages.

The air passages are the nasai passages leading from the nostrils back to the throat or pharynx, where the air passage and the food passage cross; the larynx, or voice box; and the trachea, or windpipe and its branches. The trachea divides opposite the lungs into two broncjii, and these, after entering the Iimgs, divide into smaller and smaller bronchial tubes or bronchioles, as the branches of a tree divide until the smallest twigs are reached. All of these in the figures.

The Nasal Passages. The nasal j>assages are Uned

with mucous membrane. Here end the nerves of smell,

187

Figure 121. — Diagram o£ the air passages; arrows show crossing of food and air passages in the tliroat. Air sacs of lungs and pleuri shown,

e illustrated

i88 THE

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.